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# C2 function question watch

1. I don't understand the answer to this, or how to even get there. I expanded/simplified it first, but still get the wrong answer. help. pls.

f(x) = (2x^3/2 - 3x^-3/2)^2 +5
f(x) = 5

Find the value of x to 3 sf
2. What was the original question?
3. (Original post by indignation)
I don't understand the answer to this, or how to even get there. I expanded/simplified it first, but still get the wrong answer. help. pls.

f(x) = (2x^3/2 - 3x^-3/2)^2 +5
f(x) = 5

Find the value of x to 3 sf
Would you mind posting the full question?

Edit: It looks like you've posted everything, sorry. See below.
4. (Original post by indignation)
f(x) = (2x^3/2 - 3x^-3/2)^2 +5
f(x) = 5

Find the value of x
It looks like it wants you to put

(2x^3/2 - 3x^-3/2)^2 +5 = 5

But without the full question its hard to tell (as others have said)
5. (Original post by indignation)
I don't understand the answer to this, or how to even get there. I expanded/simplified it first, but still get the wrong answer. help. pls.

f(x) = (2x^3/2 - 3x^-3/2)^2 +5
f(x) = 5

Find the value of x to 3 sf
No need to expand
if f(x) = 5 then (2x^3/2 - 3x^-3/2)^2 = 0
Solving for x from there should be straightforward

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6. (Original post by Quantum Confinement)
It looks like it wants you to put

(2x^3/2 - 3x^-3/2)^2 +5 = 5

But without the full question its hard to tell (as others have said)
yes that is right, but how do you correctly simplify the (2x^3/2 - 3x^-3/2)^2?
7. (Original post by indignation)
yes that is right, but how do you correctly simplify the (2x^3/2 - 3x^-3/2)^2?
if and only if .
8. ohhh, that makes a lot of sense
(Original post by Smaug123)
if and only if .
9. (Original post by indignation)
yes that is right, but how do you correctly simplify the (2x^3/2 - 3x^-3/2)^2?
Square root both sides then take it from there

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